A process for the generation of an oscillation with an adjustable frequency over a wide frequency range (voting - frequency) by mixing the two oscillations

摘要

660,068. Generating high-frequency oscillations. PHILIPS ELECTRICAL, Ltd., and BOOSMAN, H. B. R. April 28, 1949, No. 11329/49. Drawings to Specification. Classes 40 (v) and 40 (vi). The invention relates to circuits in which a beat frequency, variable continuously throughout a relatively wide range, is generated by mixing a first frequency which is variable throughout a narrow sub-range with a second frequency which can be varied in steps equal in width to the sub-range and avoids unwanted beats due to interaction of the beat-frequency or harmonics of it with the first or second frequencies or harmonics of them. According to the invention the values of the frequencies and the width of the sub-range are chosen such that one value of the first frequency, preferably its central value, is made equal to or an integral multiple of the width of the sub-range multiplied by the lowest common multiple of the integers next greater than the orders of all the harmonics of the beat-frequency that are to be prevented from beating with the second frequency. The first frequency may be not less than one-and-a-half times the beat frequency and the second frequency not less than half the maximum value of the beat frequency. In addition the second frequency may be less by one-and-a-half times the width of the subrange than an integral multiple of the sub-range width multiplied by the said lowest common multiple. Specification 622,838 is referred to.